Pneumatic potential-producing means.



J. A. JOHNSON & C, M. HEDMAN. PNEUMATIC POTENTIAL PRODUCING MEANS. APPLICATION FILED JUNE 24, 1911.

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APPLICATION FILED JUNE 24, 1911.

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JOHN A. JOHNSON AND CARL M. HEDMAN, OF CHICAGO, ILLINOIS, ASSIGNOBS TO THE RANSOM dz'BANDOLPI-I COMPANY, OF TOLEDO, OHIO, A. CORPORATION OF OHIO.

PNEUMATIC POTENTIAL-PRODUCING MEANS.

Specification of Letters I'atent.

Patented May 12, rare.

Uriginal application filed April 25, 1908, Serial No. 429,142. Divided and this application filed June 24,

To all to/10m ix: may concern:

Be it known that we, JOHN A. JOHNSON and CARL M. llnnMAN, both citizens of the United States. residing at Chicago, in ithc county of Cook and State of Illinois, have invented certain new and useful Improvements in Pneumatic Potential-Producing Means, of which the following is a full, clear, concise, and exact description, reference being-had tothe accompanying drawings, forming a part of this specification.

Our invention relates to pneumatic potential producing apparatus and contemplates an improved arrangement and improved construction of the parts thereof.

'l his'a r plication is divisional from our copcnding am lication, Serial No. 429,142, filed April 1908, Patent No. 999,794, dated Aug. 8. 1911.

As pointed out in our copending application referred to, the potention producing apparatus of our invention is particularly adapted for use as part of a so-called inlay casting" equipment, such as is used by prescut-day dentists in the making of fillings for teeth.

it will appear, however, that our inven lion may have other advantageous uses and we contemplate its variedapplication in this respect. although, as will be seen. a pe-' culiar relationship exists between the potential producing apparatus and the flask arrangcmcuit to form a simple. useful. and unique casting outfit for the purpose pointed our.

One of the main features of our invention is the disposition of the pump which is carried by the pressure or vacuum tank to form a unitary outfit. The tank is substantially cylindrical or barrel-shaped, and the pump extends axially through the tank and is secured therein, only the handle partbeing at the outside.

Another feature of our invention resides in the valve construction and, in this conneetion, it might be stated that the potential producing means of our invention may he used either as a vacuum pump or as a pressure pump, the change being made by merely reversing the valve and the pump piston.

in the specific description which follows,

Serial No. 635,110.

as an example of our invention, we explain our apparatus in the light of a vacuum pump and at the same time set forth the effective combination between it andthe inlay casting apparatus.

In the accompanying drawings, Figure .1 is a front elevational view of our device; Fig. 2 is a side elevational view thereof; Fig. 3 is a longitudinal sectional view taken on the plane of the line 3-3 of Fig. '1 and looking in the direction indicated by the arrows; Fig. 4 is a fragmentary longitudinal sectional view of one and of the pui np, showmg the valve mechanism on a larger scale;

Fig. 5 is a crossseetional view taken on the.

plane of the line 55 of Fig. 4 and looking in the direction indicated by the arrows; and Fig. 6 is an enlarged face view of the ,valve disk which we employ.

The pressure or vacuum tank 1 may be cylindrical or more or less barrel-shaped, as shown, and is provided with a plurality of feet 2-2 by means of which it may be rigidly secured to a suitable support. The cylindrical pump 9 which we employ comprises the pump barrel 3 having the guide head 4 for the piston ro'd and at its other end the barrel 0r cylinder 3 is closed by the valve frame 6. The outer end of the piston rod 5, which rides in "H1 axial opening in the guide head 4. terminates in a handle or knob 7. while at the other end there is seecured thereto the plunger 8, of leather or similar material. between the wasl 'rs'9 and 10 held in place by nuts 11 and 12.

The valve frame 6 has the inner bore sec tion 18. the intermediate bore section 14, of-

larger diameter, and the outer threaded bore section 15 which is engaged by a nut 16 having the axial passageway 17 therethrongh. \Vithin the bore part or compartment 14, the valve disk 18, whose form is best shown in Fig. 6, is disposed. This disk is made by cutting semi-circular notches in the edge of the circular disk to leave the by passes 19, 19.

Brazed to the front end of the pump barrel is a sleeve 23 having-a threaded portion for engaging in the threaded opening 25 through the front head of the tank, the outer portion of the sleeve being polygonal so that a wrench. may be applied. A washer ill rearwardly, the valve disk is thrown against 26, of lead or other suitable material, is in I terposed between the head of the sleeve 23 and the head of the tank so that an airtight fit will result. l'lhe rear end of the pump I extends into and is supported in a niche 27 i in the rear head of the tank. The entire ump structure can readily be unscrewed l odily from the tank. The guide head 4 is I held in the barrel or cylinder 3 by means i of a screw 28 and by removing this screw 1 the head, the stem, and the plunger may be easily removed. By removing the nut 16 the valve member 18 may be removed, and it will thus be seen that the various parts are all of convenient access and of simple and economical construction.

When the pump rod is pulled out air is Wibhdrawn from the tank into the pump barrel, the valve disk during this outward movement offthe plunger resting against the shoulder or. seat 19, at the left end of the valve compartment 14 and the air can flow from the tank through the by-passes '19 and inlothe pump barrel, the passageway 13 being large enough for this purpose. When the plunger comes to rest or is moved the inner face of the nut 16, this face being within. the area of the lay-passes 19, so that the passage 17 "will be closed, and the reduced pressure in the tank is thus maintained. The air which was drawn into the barrel upon the outward movement; of the plunger will pass by the flexible plunger edges when the plunger is moved inwardly. Upon outward movement of the plunger the air in from thereof escapes to the outside atmosphere through the passageways 20, 20, through the heade. The pressure in the tank may be indicated by a pressure gage 21 suitably mounted thereon and pneumatically connected therewith. As an ad- ,ditional feature, a bufi'er spring 22 encircles the pump rod and acts as a cushion for the plunger when the latter reaches the outer end of the barrel. It. will be seen from the above description. that we have produced a unitary struc'iiure by mounting the flask or casting device on the tank and by having the pump ri gidly attached to the tankthat is, rigid with respect to the tank irnjche sense that it is not. separate "from the tank, but is carried with it.

We shall now proceed. to describe the structure wherein the pressure potential producing means forms a part of a vacuum casting; system for making dental inlays.

A Tqnember 29 is screwed into the top of thefront end of the tank and at the ends of the cross piece carries the valve members 30 and 81 to which are secured the elbow members 3.2 and 33, respectively. Mounted on the elbow 32 is a cap member 342- and mounted upon the elbow is a cup member Each cup member has a vcirical boasoa flange 36 and a planed horizontal annular The inner section of the cup base is provided with grooves 30 which connect with the passageway 41 leading through the cup member and through the various connecting memhers to the tank when the corresponding valve is open.

in practice, a wax pattern of the filling in be made is suspended in the flask and the investment compound such as plaster Paris. is poured about. the pattern. When the compound has dried suiiiciently and har- (l01l(3( l,tl16ll1$k is placed on its cup and heated to cause absorption of the wax. thus leaving a cavity. Gold or other suitable inlaying: material is then fed to the-cavity in a liquid state. the corresponding valve being open so as to connect the cup with the low pressure. The melted material is drawn in by suction and is forccd into the various parts of the cavity however intricate, and a duplicate of the wax pattern is formed. Then the valve may be closed and the flaskcooled and the mold is then broken up so that the filling may be extracted.

in dental work, many other appliances are used during work on a patient -such appliances as a carbureter.v for instance, for supplying gas. Devices of this kind are usually small and easily misplaced and our tank body would form a very efficient support for devices of this kind. in Fig. 1 we a show a carburetor C supported from. one side of the tank.

We claim as new anddesirc to secure by Letters Patent: v

1. In combination. a portable .lank, a pump barreljrigidly connected to said tank and extending'through the interior of said tank, valve controlled communication between said tank and said barrel, :1 piston arranged to reciprocate in said barrel, and a casting device rigidly secured to the top of,

said tank, the tank, the pump. and the casting device being thus rigidly carried together as a unitary structure.

2. In combination, a portable tank, a complete pump mounted in said tank. said pump serving to exhaust the air from said tank. and a casting device rigidly secured to said tank and extending outwardly therefrom, the tank, the pump, and the casting device beingv thus carried together as a unitary structure. I

3.111 combination, a portable tank a unitary structure.

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interior of said tank, and said tank, pump, pump, and the casting device being,- thus and .fiask being thus carried together as 2 carried together as a unitary structure.

In Witness whereof, we hereunto subscribe 5. In combination, a portable tank, at our names this 21st day of June, 1911. complete pump rigidly attached to said JOHN A. JOHNSON. tank, said pump having pneumatic connec- CARL M. HEDMAN. tion with said tank, and a casting device mounted with said'tank and having pneumatic connection therewith, the tank, the

Witnesses:

HERBERT R. HEDMAN, ARTHUR H. BOE'I'ICHER. 

